Conventionally, facilities installed in factories, etc., are typically secured to the floor surfaces with anchor bolts. For example, the equipment 51 shown in FIG. 13 is installed via nuts 54 on a concrete floor surface F with anchor bolts 53 that penetrate leg portions 52. However, there are types of equipment for which anchor bolts 53 cannot be used as means for preventing its toppling. For example, pieces of equipment on production lines of drinking water or food or in kitchens are installed with their legs set on waterproof floor surfaces F without using anchor bolts in order to meet the hygienic requirements and ensure the transportability of the equipment.
Additionally, seismic isolation structures with vibration-proof rubber interposed between the equipment and the floor surfaces are widely used for the ease of their installation. Patent Document 1 proposes a technology for preventing toppling of a gravestone by embedding spherical bodies in elastic sheets, interposing the elastic sheets between the middle stone and the headstone, and allowing plastic deformation of the spherical bodies to efficiently absorb the vibrations of an earthquake.